Stepped-width co-spiral inductor structure

ABSTRACT

A stepped-width, co-spiral inductor structure includes a first exterior layer having a first exterior width. The stepped-width, co-spiral inductor structure also includes a first interior layer coupled to the first exterior layer. The first interior layer includes a first interior width that is wider than the first exterior width of the first exterior layer. The stepped-width, co-spiral inductor structure further includes a second exterior layer coupled to the first interior layer. The second exterior layer includes a second exterior width that is narrower than the first interior width of the first interior layer.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit under 35 U.S.C. § 119(e) toU.S. Provisional Patent Application No. 62/366,918, entitledSTEPPED-WIDTH CO-SPIRAL INDUCTOR STRUCTURE, filed on Jul. 26, 2016, inthe names of KIM et al., the disclosure of which is expresslyincorporated by reference herein in its entirety.

BACKGROUND Field

Aspects of the present disclosure relate to semiconductor devices, andmore particularly to a stepped-width, co-spiral inductor structure forhigh quality (Q)-factor radio frequency (RF) applications.

Background

The process flow for semiconductor fabrication of integrated circuits(ICs) may include front-end-of-line (FEOL), middle-of-line (MOL), andback-end-of-line (BEOL) processes. The front-end-of-line process mayinclude wafer preparation, isolation, well formation, gate patterning,spacer, extension and source/drain implantation, silicide formation, anddual stress liner formation. The middle-of-line process may include gatecontact formation. Middle-of-line layers may include, but are notlimited to, middle-of-line contacts, vias or other layers within closeproximity of the semiconductor device transistors or other like activedevices. The back-end-of-line process may include a series of waferprocessing steps for interconnecting the semiconductor devices createdduring the front-end-of-line and middle-of-line processes.

Successful fabrication of modern semiconductor chip products involvesinterplay between the materials and the processes employed. Inparticular, the formation of conductive material plating for thesemiconductor fabrication in the back-end-of-line processes is anincreasingly challenging part of the process flow. This is particularlytrue in terms of maintaining a small feature size. The same challenge ofmaintaining a small feature size also applies to all RF passivetechnologies, where high-performance components such as inductors andcapacitors are built upon a highly insulative substrate that may alsohave a very low loss.

Passive on glass devices involve high-performance inductor and capacitorcomponents that have a variety of advantages over other technologies,such as mount technology or multi-layer ceramic chips that are commonlyused in the fabrication of mobile radio frequency (RF) chip designs(e.g., mobile RF transceivers). The design complexity of mobile RFtransceivers is complicated by the migration to a deep sub-micronprocess node due to cost and power consumption considerations. Mobile RFtransceiver design is further complicated by added circuit functions tosupport communication enhancements. Further design challenges for mobileRF transceivers include analog/RF performance considerations, includingmismatch, noise and other performance considerations. The design ofthese mobile RF transceiver includes the use of passive devices to, forexample, suppress resonance, and/or to perform filtering, bypassing, andcoupling in high power, system on chip devices, such as applicationprocessors and graphics processors.

SUMMARY

A stepped-width, co-spiral inductor structure includes a first exteriorlayer having a first exterior width. The stepped-width, co-spiralinductor structure also includes a first interior layer coupled to thefirst exterior layer. The first interior layer includes a first interiorwidth that is wider than the first exterior width of the first exteriorlayer. The stepped-width, co-spiral inductor structure further includesa second exterior layer coupled to the first interior layer. The secondexterior layer includes a second exterior width that is narrower thanthe first interior width of the first interior layer.

A method of fabricating stepped-width, co-spiral inductor structureincludes fabricating a first exterior layer having a first exteriorwidth in a substrate. The method also includes fabricating a firstinterior layer coupled to the first exterior layer in the substrate. Thefirst interior layer includes a first interior width that is wider thanthe first exterior width of first exterior layer. The method furtherincludes fabricating a second exterior layer coupled to the firstinterior layer in the substrate. The second exterior layer includes asecond exterior width that is narrower than the first interior width ofthe first interior layer.

A radio frequency (RF) front-end module includes a stepped-width,laminate inductor structure. The stepped-width, laminate inductorstructure includes a stepped-width, co-spiral inductor structure in asubstrate. The stepped-width, co-spiral inductor structure includes afirst exterior layer having a first exterior width, and a first interiorlayer coupled to the first exterior layer. The first interior layer hasa first interior width that is wider than the first exterior width ofthe first exterior layer. The stepped-width, co-spiral inductorstructure also includes a second exterior layer coupled to the firstinterior layer. The second exterior layer has a second exterior widththat is narrower than the first interior width of the first interiorlayer. The RF front-end module also includes a duplexer supported by thestepped-width, laminate inductor structure.

This has outlined, rather broadly, the features and technical advantagesof the present disclosure in order that the detailed description thatfollows may be better understood. Additional features and advantages ofthe disclosure will be described below. It should be appreciated bythose skilled in the art that this disclosure may be readily utilized asa basis for modifying or designing other structures for carrying out thesame purposes of the present disclosure. It should also be realized bythose skilled in the art that such equivalent constructions do notdepart from the teachings of the disclosure as set forth in the appendedclaims. The novel features, which are believed to be characteristic ofthe disclosure, both as to its organization and method of operation,together with further objects and advantages, will be better understoodfrom the following description when considered in connection with theaccompanying figures. It is to be expressly understood, however, thateach of the figures is provided for the purpose of illustration anddescription only and is not intended as a definition of the limits ofthe present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following description taken in conjunction with theaccompanying drawings.

FIG. 1 is a diagram of a radio frequency (RF) communication system.

FIG. 2A shows a perspective of a laminate inductor structure and FIG. 2Bshows a cross-section view of the laminate inductor structure in asubstrate.

FIG. 3A shows a perspective of a stepped-width, co-spiral inductorstructure according to aspects of the present disclosure.

FIG. 3B shows a cross-section view of the stepped-width, co-spiralinductor structure of FIG. 3A arranged as a laminate inductor structureaccording to aspects of the present disclosure.

FIGS. 4A and 4B show cross-section views of stepped-width, laminateinductor structures according to aspects of the present disclosure.

FIG. 5 shows a cross-section view of a stepped-width, laminate inductorstructure according to further aspects of the present disclosure.

FIG. 6 is a cross-section view of a duplexer arranged in a poweramplifier (PA) integrated duplexer (PAMID) module or a front-end modulewith integrated duplexer (FEMID) module including a stepped-width,laminate inductor structure, according to aspects of the presentdisclosure.

FIG. 7 is a flow diagram illustrating a method of fabricating astepped-width, co-spiral inductor structure according to aspects of thedisclosure.

FIG. 8 is a block diagram showing an exemplary wireless communicationsystem in which a configuration of the disclosure may be advantageouslyemployed.

FIG. 9 is a block diagram illustrating a design workstation used forcircuit, layout, and logic design of the stepped-width, co-spiralinductor structure according to aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with theappended drawings, is intended as a description of variousconfigurations and is not intended to represent the only configurationsin which the concepts described herein may be practiced. The detaileddescription includes specific details for the purpose of providing athorough understanding of the various concepts. It will be apparent tothose skilled in the art, however, that these concepts may be practicedwithout these specific details. In some instances, well-known structuresand components are shown in block diagram form in order to avoidobscuring such concepts. As described herein, the use of the term“and/or” is intended to represent an “inclusive OR,” and the use of theterm “or” is intended to represent an “exclusive OR.”

Mobile radio frequency (RF) chip designs (e.g., mobile RF transceivers)have migrated to a deep sub-micron process node due to cost and powerconsumption considerations. The design complexity of mobile RFtransceivers is further complicated by added circuit functions tosupport communication enhancements, such as carrier aggregation. Furtherdesign challenges for mobile RF transceivers include analog/RFperformance considerations, including mismatch, noise, and otherperformance considerations. The design of these mobile RF transceiversincludes the use of passive devices, for example, to suppress resonanceand/or to perform filtering, bypassing, and coupling.

Passive on glass devices involve high-performance inductor and capacitorcomponents that have a variety of advantages over other technologies,such as surface mount technology or multi-layer ceramic chips. Theseadvantages include being more compact in size and having smallermanufacturing variations. Passive on glass devices also involve a higherquality (Q)-factor value that meets stringent low insertion loss and lowpower consumption specifications. Devices such as inductors may beimplemented as three-dimensional (3D) structures with passive on glasstechnologies. 3D inductors or other 3D devices may also experience anumber of design constraints due to their 3D implementation.

An inductor is an example of an electrical device used to temporarilystore energy in a magnetic field within a wire coil according to aninductance value. This inductance value provides a measure of the ratioof voltage to the rate of change of current passing through theinductor. When the current flowing through an inductor changes, energyis temporarily stored in a magnetic field in the coil. In addition totheir magnetic field storing capability, inductors are often used inalternating current (AC) electronic equipment, such as radio equipment.For example, the design of mobile RF transceivers includes the use ofinductors with improved inductance density while reducing magnetic lossat high frequency (e.g., 500 megahertz (MHz) to 5 gigahertz (GHz) RFrange).

Various aspects of the disclosure provide techniques for fabrication ofa skewed, co-spiral inductor structure. The process flow forsemiconductor fabrication of the skewed, co-spiral inductor structuremay include front-end-of-line (FEOL) processes, middle-of-line (MOL)processes, and back-end-of-line (BEOL) processes. It will be understoodthat the term “layer” includes film and is not to be construed asindicating a vertical or horizontal thickness unless otherwise stated.As described herein, the term “substrate” may refer to a substrate of adiced wafer or may refer to a substrate of a wafer that is not diced.Similarly, the terms chip and die may be used interchangeably unlesssuch interchanging would tax credulity. As described herein, the term“passive substrate” may refer to a substrate of a diced wafer or panel,or may refer to the substrate of a wafer/panel that is not diced. In oneconfiguration, the passive substrate is comprised of glass, quartz,sapphire, high-resistivity silicon, or other like passive material. Thepassive substrate may also be a coreless substrate.

As described herein, the back-end-of-line interconnect layers may referto the conductive interconnect layers (e.g., metal one (M1), metal two(M2), metal three (M3), etc.) for electrically coupling tofront-end-of-line active devices of an integrated circuit. Theback-end-of-line interconnect layers may electrically couple tomiddle-of-line interconnect layers for, for example, connecting M1 to anoxide diffusion (OD) layer of an integrated circuit. A back-end-of-linefirst via (V2) may connect M2 to M3 or others of the back-end-of-lineinterconnect layers. The front-end-of-line processes may include the setof process steps that form the active devices, such as transistors,capacitors, and diodes. The front-end-of-line processes include ionimplantation, anneals, oxidation, CVD (chemical vapor deposition) or ALD(atomic layer deposition), etching, CMP (chemical mechanical polishing),and epitaxy.

The middle-of-line processes may include the set of process steps thatenable connection of the transistors to the back-end-of-lineinterconnects (e.g., M1 . . . M8). These steps include silicidation andcontact formation as well as stress introduction. The back-end-of-lineprocesses may include the set of process steps that form theinterconnect that ties the independent transistors and form circuits.Currently, copper and aluminum are used to form the interconnects usingvarious process technology such as sputtering, spraying, and plating,but with further development of the technology, other conductivematerials may be used.

According to aspects of the present disclosure, a duplexer may bearranged in a power amplifier (PA) integrated duplexer (PAMID) module ora front-end module with integrated duplexer (FEMID) module, in which theduplexer is integrated with a laminate substrate inductor, such as alaminate integrated inductor. The use of laminate integrated inductorsmay replace the use of surface mount devices within RF front-end modulesdue to spacing constraints. Unfortunately, the area occupied by thelaminate integrated inductors within a substrate (e.g., a packagesubstrate) may also be constrained due to customer specifications. Forexample, the substrate generally includes ground planes to meetisolation specifications to avoid interference between the laminateintegrated inductors and the duplexers. Unfortunately, the ground planesof the substrate may compress a magnetic field of the laminateintegrated inductors, which reduces the quality (Q)-factor when thelaminate integrated inductors are arranged within a laminate substrate.

Aspects of the present disclosure describe a stepped-width, co-spiralinductor structure for high quality (Q)-factor radio frequency (RF)applications. In one arrangement, the stepped-width, co-spiral inductorstructure includes a first exterior layer (e.g., a first exterior spiralinductor) having a width. In addition, the inductor structure includes afirst interior layer (e.g., a first interior spiral inductor) coupled tothe first exterior layer. In this arrangement, the first interior layerhas a width that is wider than the width of the first exterior layer.The inductor structure also includes a second exterior layer (e.g., asecond exterior spiral inductor) coupled to the first interior layer. Inthis arrangement, the second exterior layer has a width that is narrowerthan the width of the first interior layer. The width of the secondexterior layer may be the same as the width of the first exterior layer.In an alternative arrangement, the width of the second exterior layer isgreater than or less than the width of the first exterior layer.

In contrast to conventional inductors, which specify a co-spiralinductor with inductor traces having a fixed width, the improvedinductor design is a stepped-width, co-spiral inductor structure withnarrower trace widths near top and bottom ground planes to reduceinductor area and improve a quality (Q)-factor of the inductorstructure. The inductor may be a laminate substrate inductor, in whichthe substrate supports a duplexer. The improved stepped-width, co-spiralinductor structure may exhibit a significant quality (Q)-factorimprovement (e.g., 8.25% at 800 MHz). The improved stepped-width,co-spiral inductor structure also occupies a reduced area (e.g., 29%reduction) and has an improved duplexer insertion loss (e.g., 0.05 dB).

One goal driving the wireless communication industry is providingconsumers with increased bandwidth. The use of carrier aggregation incurrent generation communications provides one possible solution forachieving this goal. For wireless communication, passive devices areused to process signals in carrier aggregation systems. In these carrieraggregation systems, signals are communicated with both high band andlow band frequencies. In a radio frequency front-end (RFFE) module, apower amplifier (PA) may be integrated with a passive device (e.g., aduplexer) to provide a PAMID module. In addition, a front-end module maybe integrated with a duplexer to provide a FEMID module. A duplexer(e.g., an acoustic filter) may be configured for simultaneoustransmission and reception within the same band (e.g., a low band) tosupport carrier aggregation.

FIG. 1 is a schematic diagram of a radio frequency (RF) communicationssystem 100 including a stepped-width, co-spiral inductor structureintegrated with a duplexer 180 according to an aspect of the presentdisclosure. Representatively, the RF communications system 100 includesa WiFi module 170 having a first diplexer 190-1 and an RF front-endmodule 150 including a second diplexer 190-2 for a chipset 160 toprovide carrier aggregation according to an aspect of the presentdisclosure. The WiFi module 170 includes the first diplexer 190-1communicably coupling an antenna 192 to a wireless local area networkmodule (e.g., WLAN module 172). The RF front-end module 150 includes thesecond diplexer 190-2 communicably coupling an antenna 194 to a wirelesstransceiver (WTR) 120 through the duplexer 180. The wireless transceiver120 and the WLAN module 172 of the WiFi module 170 are coupled to amodem (mobile station modem (MSM), e.g., baseband modem) 130 that ispowered by a power supply 152 through a power management integratedcircuit (PMIC) 156.

The chipset 160 also includes capacitors 162 and 164, as well as aninductor(s) 166 to provide signal integrity. The PMIC 156, the modem130, the wireless transceiver 120, and the WLAN module 172 each includecapacitors (e.g., 158, 132, 122, and 174) and operate according to aclock 154. The geometry and arrangement of the various inductor andcapacitor components in the chipset 160 may reduce the electromagneticcoupling between the components. The RF communications system 100 mayalso include a power amplifier (PA) integrated with the duplexer 180(e.g., a PAMID module). The duplexer 180 may filter the input/outputsignals according to a variety of different parameters, includingfrequency, insertion loss, rejection or other like parameters. Accordingto aspects of the present disclosure, the duplexer 180 may be integratedwith a stepped-width, co-spiral inductor structure, for example, asshown in FIGS. 3A to 6.

FIG. 2A shows a plan view 201 of an inductor structure 200 and FIG. 2Bshows a cross-section view 252 of a laminate inductor structure 250arranged in a substrate 202. Representatively, the inductor structure200 is composed of a first trace 210-1, a second trace 210-2, a thirdtrace 210-3, and a fourth trace 210-4, each having a fixed width W. Thefirst trace 210-1, the second trace 210-2, the third trace 210-3, andthe fourth trace 210-4 are arranged in overlapping spiral patternscoupled at a trace beginning/end of the inductor structure 200 using avia 212. The inductor structure 200 is arranged according to amulti-turn configuration. The inductor structure 200 may be within asubstrate, for example, as shown in FIG. 2B.

FIG. 2B shows the cross-section view 252 of the laminate inductorstructure 250 within the substrate 202 according to aspects of thepresent disclosure. Representatively, the inductor structure 200 of FIG.2A is within a substrate 202 including a first ground plane 204 and asecond ground plane 206 to form the laminate inductor structure 250. Thefirst ground plane 204 may be formed from a first interconnect layer M1,and the second ground plane 206 may be formed from an eighthinterconnect layer M8. The first ground plane 204 and the second groundplane 206 are generally arranged to meet inter-module shieldingspecifications within, for example, an RF front-end module.

The substrate 202 may be a package substrate, an interposer, a laminatesubstrate, a passive substrate, or other like substrate. The first trace210-1 may be fabricated using a third interconnect layer M3, and thesecond trace 210-2 may be fabricated using a fourth interconnect layerM4. In addition, the third trace 210-3 may be fabricated using a fifthinterconnect layer M5, and the fourth trace 210-4 may be fabricatedusing a sixth interconnect layer M6. In this arrangement, each of theinductive traces (e.g., 210) has a fixed width W and the substrate doesnot include a second interconnect layer M2 or a seventh interconnectlayer M7.

According to aspects of the present disclosure, a duplexer may bearranged in a power amplifier (PA) integrated duplexer (PAMID) module ora front-end module with integrated duplexer (FEMID) module, in which theduplexer is integrated with a laminate substrate inductor, such as thelaminate inductor structure 250. The use of laminate integratedinductors may replace the use of surface mount devices within, forexample, the RF front-end module 150 (FIG. 1) due to spacingconstraints. Unfortunately, the area occupied by the laminate inductorstructure 250 within the substrate 202 is also constrained due tocustomer specifications. For example, the substrate 202 includes thefirst ground plane 204 and the second ground plane 206 to meet isolationspecifications to avoid interference between the laminate integratedinductors and the duplexers. The first ground plane 204 and the secondground plane 206 of the substrate 202 may compress a magnetic field ofthe laminate inductor structure 250, which reduces the quality(Q)-factor when the laminate inductor structure is arranged as shown inFIGS. 2A and 2B.

FIG. 3A shows a plan view 301 of a stepped-width, co-spiral inductorstructure, and FIG. 3B shows a cross-section view of the stepped-width,co-spiral inductor of FIG. 3A, arranged as a laminate inductor structureaccording to aspects of the present disclosure. In contrast to theinductor structure 200 shown in FIG. 2A, which specifies a co-spiralinductor with inductor traces having a fixed width, FIG. 3A illustratesthe plan view 301 of a stepped-width, co-spiral inductor structure 300having narrower trace widths proximate top and bottom ground planes toreduce inductor area and improve a quality (Q)-factor of the inductorstructure, according to aspects of the present disclosure.

Representatively, the stepped-width, co-spiral inductor structure 300includes a first exterior trace 310-1 (e.g., a first exterior layer) anda second exterior trace 310-2 (e.g., a second exterior layer). The firstexterior trace 310-1 has a first exterior trace width W1 (e.g., a firstexterior width), and the second exterior trace 310-2 has a secondexterior trace width W4 (e.g., a second exterior width), which may ormay not equal the first exterior trace width W1. The stepped-width,co-spiral inductor structure 300 also includes a first interior trace320-1 (e.g., a first interior layer) and a second interior trace 320-2(e.g., a second interior layer). The first exterior trace 310-1, thefirst interior trace 320-1, the second interior trace 320-2, and thesecond exterior trace 310-2 are arranged in overlapping spiral patternscoupled at a trace beginning/end of the stepped-width, co-spiralinductor structure 300 using a via 312. The stepped-width, co-spiralinductor structure 300 is arranged according to a multi-turnconfiguration.

The first interior trace 320-1 has a first interior trace width W2(e.g., a first interior width), and the second interior trace 320-2 hasa second interior trace width W3 (e.g., a second interior width). Thefirst interior trace width W2 equals the second interior trace width W3;however, the second interior trace width W3 may be different from thefirst interior trace width W2. In this aspect of the present disclosure,the first interior trace width W2 and the second interior trace width W3are each greater than the first exterior trace W1 and the secondexterior trace width W4. In this arrangement, the first exterior tracewidth W1 equals the second exterior trace width W4; however, the secondexterior trace width W4 may be different from the first exterior tracewidth W1. The stepped-width, co-spiral inductor structure 300 may bewithin a substrate, for example, as shown in FIG. 3B.

FIG. 3B shows a cross-section view 352 of the stepped-width, co-spiralinductor structure 300 of FIG. 3A, arranged as a stepped-width, laminateinductor structure 350 according to aspects of the present disclosure.Representatively, the stepped-width, co-spiral inductor structure 300 ofFIG. 3A is within a substrate 302, including a first ground plane 304and a second ground plane 306 to form the stepped-width, laminateinductor structure 350. The first ground plane 304 is also formed from afirst interconnect layer M1, and the second ground plane 306 is alsoformed from an eighth interconnect layer M8. The first ground plane 304and the second ground plane 306 are arranged to meet inter-moduleshielding specifications within, for example, the RF front-end module150 shown in FIG. 1.

The substrate 302 may be a package substrate, an interposer, a laminatesubstrate, a passive substrate, or other like substrate. The firstexterior trace 310-1 may be fabricated using a third interconnect layerM3, and the second exterior trace 310-2 may be fabricated using a sixthinterconnect layer M6. In addition, the first interior trace 320-1 maybe fabricated using a fourth interconnect layer M4, and the secondinterior trace 320-2 may be fabricated using a fifth interconnect layerM5. In this arrangement, the first interior trace width W2 equals thesecond interior trace width W3, and the first exterior trace width W1equals the second exterior trace width W4. In addition, the substrate302 does not include a second interconnect layer M2 or a seventhinterconnect layer M7.

The stepped-width, laminate inductor structure 350 may support aduplexer on the substrate 302, for example, as shown in FIG. 6. Theimproved stepped-width, co-spiral inductor structure may exhibit asignificant quality (Q)-factor improvement (e.g., 8.25% at 800 MHz) byhaving narrower trace widths proximate top and bottom ground planes of asubstrate. For example, a stepped-width, co-spiral inductor structure300 may exhibit a quality (Q)-factor of 21 at 800 MHz, compared to afactor of 19 at 800 MHz exhibited by the inductor structure 200 of FIG.2A. The stepped-width, co-spiral inductor structure 300 also occupies areduced area (e.g., 29% reduction) and has an improved insertion loss(e.g., 0.05 dB), when arranged as shown in FIG. 3B.

FIG. 4A shows a cross-section view 401 of a stepped-width, laminateinductor structure 400 according to aspects of the present disclosure.Representatively, the stepped-width, laminate inductor structure 400includes a substrate 402 having a first ground plane 404 and a secondground plane 406 to shield inter-module RF components from the magneticfields of the laminate inductor structure 400. The first ground plane404 is formed from a first interconnect layer M1, and the second groundplane 406 is formed from a seventh interconnect layer M7. In thisarrangement, however, an interconnect layer 460 (e.g., the eighthinterconnect layer M8) may be used to communicate a digital signal.

In this aspect of the present disclosure, the use of the interconnectlayer 460 for communicating a digital signal reduces the inductor areaavailable between the first ground plane 404 and the second ground plane406. The first ground plane 404 and the second ground plane 406 arearranged to meet inter-module shielding specifications within, forexample, the RF front-end module 150 shown in FIG. 1. The substrate 402may be a package substrate, an interposer, a laminate substrate, apassive substrate, or other like substrate. This arrangement, therefore,reduces the available area for formation of an inductor structure. Tomeet the reduced area specification, the stepped-width, laminateinductor structure 400 includes an interior trace 420, rather than themultiple interior traces of the stepped-width, laminate inductorstructure 350 shown in FIG. 3B.

In this aspect of the present disclosure, the stepped-width, laminateinductor structure 400 includes a first exterior trace 410-1 fabricatedusing a third interconnect layer M3, and a second exterior trace 410-2fabricated using a fifth interconnect layer M5. In addition, theinterior trace 420 may be fabricated using a fourth interconnect layerM4. A first exterior trace width W1 of the first exterior trace 410-1equals a second exterior trace width W3 of the second exterior trace410-2, which are both less than an interior trace width W2 of theinterior trace 420. Although the substrate 402 does not include a secondinterconnect layer M2 or a sixth interconnect layer M6, the addition ofthe interconnect layer 460 increases compression of the magnetic fieldproduced by the stepped-width, laminate inductor structure 400. Asnoted, the additional compression is compensated for by removing thesecond interior trace 320-2 (FIG. 3B) from the stepped-width, laminateinductor structure 400.

FIG. 4B shows a cross-section view 451 of a stepped-width, laminateinductor structure 450 according to aspects of the present disclosure.As will be recognized, a configuration of the stepped-width, laminateinductor structure 450 is similar to the configuration of thestepped-width, laminate inductor structure 400 of FIG. 4A. In theconfiguration shown in FIG. 4B, however, the first exterior trace 410-1is fabricated using a second interconnect layer M2, and the secondexterior trace 410-2 is fabricated using a sixth interconnect layer M6.In addition, a first interior trace 420-1 is fabricated using a thirdinterconnect layer M3, and a second interior trace 420-2 is fabricatedusing a fifth interconnect layer M5. A third interior trace 420-3 (e.g.,a third interior layer), fabricated using a fourth interconnect layerM4, is between the first interior trace 420-1 and the second interiortrace 420-2.

The first exterior trace 410-1 and the second exterior trace 410-2 eachhave the same first exterior trace width W1. Similarly, the firstinterior trace 420-1 and the second interior trace 420-2 each have thesame second interior trace width W2, which is greater than the firstexterior trace width W1 of the first exterior trace 410-1 and the secondexterior trace 410-2. In addition, a third interior trace width W3(e.g., a third interior width) of the third interior trace 420-3 isgreater than the second interior trace width W2 of the first interiortrace 420-1 and the second interior trace 420-2.

Additional compression due to the third interior trace 420-3 iscompensated for by further reducing the trace width (W1) of the firstexterior trace 410-1 and the second exterior trace 410-2 as well as thetrace width (W2) the first interior trace 420-1 and the second interiortrace 420-2 to form the stepped-width, laminate inductor structure 450.

FIG. 5 shows a cross-section view 501 of a stepped-width, laminateinductor structure 500 according to aspects of the present disclosure.Representatively, the stepped-width, laminate inductor structure 500includes a substrate 502, having a first ground plane 504 and a secondground plane 506 to shield inter-module RF components from the magneticfields of the stepped-width, laminate inductor structure 500. In thisarrangement, however, the first ground plane 504 is formed from a secondinterconnect layer M2, and the second ground plane 506 is formed from asixth interconnect layer M6. In this aspect of the present disclosure, afirst interconnect layer 550 (e.g., the first interconnect layer M1) maybe used to communicate a signal. In addition, a second interconnectlayer 560 (e.g., the seventh interconnect layer M7) and a thirdinterconnect layer 570 (e.g., the eighth interconnect layer M8) may beused to provide signal communication or other like function rather thanoperating as a ground layer.

In this aspect of the present disclosure, the use of the firstinterconnect layer 550, the second interconnect layer 560, and the thirdinterconnect layer 570 for signal communication (e.g., digital signalcommunication) reduces the inductor area available between the firstground plane 504 and the second ground plane 506, which are arranged tomeet inter-module shielding specifications within, for example, the RFfront-end module 150 shown in FIG. 1. This arrangement, therefore,further reduces the available area for formation of an inductorstructure. To meet the reduced area specification, the stepped-width,laminate inductor structure 500 includes an interior trace 520, ratherthan the multiple interior traces of the stepped-width, laminateinductor structure 350 shown in FIG. 3B.

In this aspect of the present disclosure, the stepped-width, laminateinductor structure 500 includes a first exterior trace 510-1 fabricatedusing the third interconnect layer M3, and a second exterior trace 510-2fabricated using the fifth interconnect layer M5. In addition, theinterior trace 520 may be fabricated using the fourth interconnect layerM4. In this arrangement, the first exterior trace width W1 of the firstexterior trace 510-1 equals the second exterior trace width W3 of thesecond exterior trace 510-2, which are both less than an interior tracewidth W2 of the interior trace 520. The addition of the firstinterconnect layer 550, the second interconnect layer 560, and the thirdinterconnect layer 570 further increases compression of the magneticfield produced by the stepped-width, laminate inductor structure 500.According to aspects of the present disclosure, the additionalcompression is compensated for by removing the second interior trace320-2 (FIG. 3B) and further adjusting the trace width of thestepped-width, laminate inductor structure 500.

FIG. 6 is a cross-section view 601 of a duplexer 680 arranged in a poweramplifier (PA) integrated duplexer (PAMID) module or a front-end modulewith integrated duplexer (FEMID) module 600 including a stepped-width,laminate inductor structure, according to aspects of the presentdisclosure. In this arrangement, the duplexer 680 is supported by astepped-width, laminate inductor structure, such as the laminateinductor structure 350, as shown in FIG. 3B. The use of laminateintegrated inductors may replace the use of surface mount deviceswithin, for example, the RF front-end module 150 (FIG. 1) due to spacingconstraints. In particular, the area occupied by the laminate inductorstructure within a substrate 602 is constrained due to customerspecifications. For example, the substrate 602 includes a first groundplane 604 and a second ground plane 606 to meet isolation specificationsto avoid interference between the laminate inductor structure within amatching inductor region 630 and the duplexer 680. Unfortunately, thefirst ground plane 604 and the second ground plane 606 of the substrate602 may compress a magnetic field of the laminate inductor structure,which reduces the quality (Q)-factor when the laminate inductorstructure is arranged within the matching inductor region 630.

In this aspect of the present disclosure, the matching inductor region630 includes a stepped-width, laminate inductor structure within thesubstrate 602. The substrate 602 includes a first exterior trace 610-1fabricated using the second interconnect layer M2, and a second exteriortrace 610-2 fabricated using the fifth interconnect layer M5. Thesubstrate 602 also includes a first interior trace 620-1 and a secondinterior trace 620-2. The first interior trace 620-1 may be fabricatedusing the third interconnect layer M3, and the second interior trace620-2 may be fabricated using the fourth interconnect layer M4. In thisarrangement, a first exterior trace width W1 of the first exterior trace610-1 equals a second exterior trace width W4 of the second exteriortrace 610-2, which are both less than a first interior trace width W2 ofthe first interior trace 620-1 and a second interior trace width W3 ofthe second interior trace 620-2.

The PAMID/FEMID module 600 also includes the duplexer 680 supported bythe substrate 602. The duplexer 680 is coupled to the first ground plane604 through conductive bumps 682 and 684 (e.g., solder balls). ThePAMID/FEMID module 600 also includes a module shielding layer 640surrounding the duplexer 680 and the substrate 602. In addition, thePAMID/FEMID module 600 may be supported by a system board (not shown),such as a printed circuit board (PCB), a system board, or other likeboard. The stepped-width, laminate inductor structure in the matchinginductor region 630 of the PAMID/FEMID module 600 may exhibit asignificant quality (Q)-factor improvement by having a narrower tracewidths proximate top and bottom ground planes of the substrate 602.

Furthermore, the PAMID/FEMID module may show improved insertion loss inthe pass band, leading to many benefits in PA efficiency, power saving,etc. According to aspects of the present disclosure, the area occupiedby the stepped-width, laminate inductor structure may be reduced (e.g.,29% reduction). The reduced area occupied by the stepped-width, laminateinductor structure in the matching inductor region 630 prevents thefirst ground plane 604 and the second ground plane 606 of the substrate602 from compressing the magnetic field of the laminate integratedinductor. As a result the quality (Q)-factor of the laminate integratedinductor is not degraded. In addition, the duplexer may exhibit improvedinsertion loss (e.g., 0.05 dB), in a PAMID/FEMID module 600 as shown inFIG. 6.

FIG. 7 is a flow diagram illustrating a method 700 of fabricating astepped-width, co-spiral inductor structure according to aspects of thepresent disclosure. At block 702, a first exterior layer having a firstexterior width is fabricated in a substrate. For example, as shown inFIG. 3B, the first exterior trace 310-1 is fabricated in the substrate302, proximate to a first ground plane 304 of a substrate 302. At block704, a first interior layer coupled to the first exterior layer isfabricated in the substrate. The first interior layer may have a firstinterior width that is wider than the first exterior width. For example,as shown in FIG. 3B, the first interior trace 320-1 is fabricated in thesubstrate 302, proximate to the first exterior trace 310-1. The firstinterior width W2 of the first interior trace 320-1 can be wider thanthe first exterior width W1 of the first exterior trace 310-1.

Referring again to FIG. 7, at block 706, a second exterior layer coupledto the first interior layer is fabricated in the substrate. The secondexterior layer may have a second exterior width that is narrower thanthe first interior width. For example, as shown in FIG. 3B, the secondexterior trace 310-2 is fabricated in the substrate 302, proximate thesecond ground plane 306. The first interior width W2 of the firstinterior trace 320-1 can be wider than the second exterior width W4 ofthe second exterior trace 310-2. According to aspects of the presentdisclosure, the second exterior width W4 of the second exterior trace310-2 may be equal to or different from the first exterior width W1 ofthe first exterior trace 310-1.

Fabricating the first exterior layer in block 702 may include patterningthe first exterior trace 310-1 by etching a conductive material in thesubstrate 302 according to a spiral pattern having the first exteriorwidth W1, for example, as shown in FIGS. 3A and 3B. In addition,fabricating the first interior layer of block 704 may include etching afirst via opening in a first separation layer to expose the firstexterior trace 310-1. The first separation layer is then patternedaccording to a first interior spiral pattern having the first interiorwidth W2. Next a conductive material is deposited in the first viaopening and the patterned first separation layer. This process may alsoinclude etching the conductive material in the patterned firstseparation layer as a first interior spiral inductor coupled to thefirst exterior layer through the first via opening.

According to aspects of the present disclosure, fabricating the secondexterior layer of block 706 may include etching a second via opening ina second separation layer to expose the first interior trace 320-1.Next, the second separation layer is patterned according to a secondexterior spiral pattern having the second exterior width W4. Aconductive material is then deposited in the second via opening and thesecond patterned separation layer. This process may be completed byetching the conductive material in the patterned second separation layeras a second exterior spiral inductor coupled to the first interiorspiral inductor through the second via opening, for example, as shown inFIG. 3A. As shown in FIG. 3B, the stepped-width, co-spiral inductor iswithin the substrate 302. The substrate 302 includes the first groundplane 304 proximate to a first exterior layer (e.g., the first exteriortrace 310-1), and the second ground plane 306 proximate the secondexterior layer (e.g., the second exterior trace 310-2), such that thefirst ground plane 304 is distal from the second ground plane 306.

The use of laminate integrated inductors may replace the use of surfacemount devices within RF front-end modules due to spacing constraints.Unfortunately, the area occupied by the laminate integrated inductorswithin a substrate (e.g., a package substrate) may also be constraineddue to customer specifications. In contrast to conventional inductors,with inductor traces having a fixed width, the improved inductor designis a stepped-width, co-spiral inductor structure with narrower tracewidths proximate top and bottom ground planes to reduce inductor areaand improve quality (Q)-factor of the inductor structure. According toaspects of the present disclosure, a duplexer may be arranged in a poweramplifier (PA) integrated duplexer (PAMID) module or a front-end modulewith integrated duplexer (FEMID) module, in which the duplexer isintegrated with a stepped-width, co-spiral inductor structure for highquality (Q)-factor radio frequency (RF) applications.

FIG. 8 is a block diagram showing an exemplary wireless communicationsystem 800 in which an aspect of the disclosure may be advantageouslyemployed. For purposes of illustration, FIG. 8 shows three of the remoteunits 820, 830, and 850 and two of the base stations 840. It will berecognized that wireless communication systems may have many more remoteunits and base stations. Remote units 820, 830, and 850 each include ICdevices 825A, 825C, and 825B having a radio frequency (RF) front-endmodule that includes the disclosed inductors. It will be recognized thatother devices may also include the disclosed inductors, such as the basestations, switching devices, and network equipment including a RFfront-end module. FIG. 8 shows forward link signals 880 from one of thebase stations 840 to the remote units 820, 830, and 850 and reverse linksignals 890 from the remote units 820, 830, and 850 to base stations840.

In FIG. 8, one of the remote units 820 is shown as a mobile telephone,one of the remote units 830 is shown as a portable computer, and remoteunit 850 is shown as a fixed location remote unit in a wireless localloop system. For example, the remote units 820, 830, and 850 may be amobile phone, a hand-held personal communication systems (PCS) unit, aportable data unit such as a personal digital assistant (PDA), a GPSenabled device, a navigation device, a set top box, a music player, avideo player, an entertainment unit, a fixed location data unit such asa meter reading equipment, or a communications device, including an RFfront-end module, that stores or retrieves data or computerinstructions, or combinations thereof. Although FIG. 8 illustratesremote units according to the aspects of the disclosure, the disclosureis not limited to these exemplary illustrated units. Aspects of thedisclosure may be suitably employed in many devices, which include thedisclosed devices.

FIG. 9 is a block diagram illustrating a design workstation used forcircuit, layout, and logic design of the stepped-width, co-spiralinductor structure disclosed above. A design workstation 900 includes ahard disk 901 containing operating system software, support files, anddesign software such as Cadence or OrCAD. The design workstation 900also includes a display 902 to facilitate design of a circuit 910 or astepped-width, co-spiral inductor structure 912. A storage medium 904 isprovided for tangibly storing the design of the circuit 910 or thestepped-width, co-spiral inductor structure 912. The design of thecircuit 910 or the stepped-width, co-spiral inductor structure 912 maybe stored on the storage medium 904 in a file format such as GDSII orGERBER. The storage medium 904 may be a CD-ROM, DVD, hard disk, flashmemory, or other appropriate device. Furthermore, the design workstation900 includes a drive apparatus 903 for accepting input from or writingoutput to the storage medium 904.

Data recorded on the storage medium 904 may specify logic circuitconfigurations, pattern data for photolithography masks, or mask patterndata for serial write tools such as electron beam lithography. The datamay further include logic verification data such as timing diagrams ornet circuits associated with logic simulations. Providing data on thestorage medium 904 facilitates the design of the circuit 910 or thestepped-width, co-spiral inductor structure 912 by decreasing the numberof processes for designing semiconductor or passive wafers.

For a firmware and/or software implementation, the methodologies may beimplemented with modules (e.g., procedures, functions, and so on) thatperform the functions described herein. A machine-readable mediumtangibly embodying instructions may be used in implementing themethodologies described herein. For example, software codes may bestored in a memory and executed by a processor unit. Memory may beimplemented within the processor unit or external to the processor unit.As used herein, the term “memory” refers to types of long term, shortterm, volatile, nonvolatile, or other memory and is not to be limited toa particular type of memory or number of memories, or type of media uponwhich memory is stored.

If implemented in firmware and/or software, the functions may be storedas one or more instructions or code on a computer-readable medium.Examples include computer-readable media encoded with a data structureand computer-readable media encoded with a computer program.Computer-readable media includes physical computer storage media. Astorage medium may be an available medium that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can include RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, orother medium that can be used to store desired program code in the formof instructions or data structures and that can be accessed by acomputer; disk and disc, as used herein, includes compact disc (CD),laser disc, optical disc, digital versatile disc (DVD) and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

In addition to storage on computer-readable medium, instructions and/ordata may be provided as signals on transmission media included in acommunication apparatus. For example, a communication apparatus mayinclude a transceiver having signals indicative of instructions anddata. The instructions and data are configured to cause one or moreprocessors to implement the functions outlined in the claims.

Although the present disclosure and its advantages have been describedin detail, it should be understood that various changes, substitutionsand alterations can be made herein without departing from the technologyof the disclosure as defined by the appended claims. For example,relational terms, such as “above” and “below” are used with respect to asubstrate or electronic device. Of course, if the substrate orelectronic device is inverted, above becomes below, and vice versa.Additionally, if oriented sideways, above and below may refer to sidesof a substrate or electronic device. Moreover, the scope of the presentapplication is not intended to be limited to the particularconfigurations of the process, machine, manufacture, and composition ofmatter, means, methods and steps described in the specification. As oneof ordinary skill in the art will readily appreciate from thedisclosure, processes, machines, manufacture, compositions of matter,means, methods, or steps, presently existing or later to be developedthat perform substantially the same function or achieve substantiallythe same result as the corresponding configurations described herein maybe utilized according to the present disclosure. Accordingly, theappended claims are intended to include within their scope suchprocesses, machines, manufacture, compositions of matter, means,methods, or steps.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the disclosure herein may be implemented as electronichardware, computer software, or combinations of both. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the disclosure herein may be implemented or performedwith a general-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm described in connection with thedisclosure may be embodied directly in hardware, in a software moduleexecuted by a processor, or in a combination of the two. A softwaremodule may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers,hard disk, a removable disk, a CD-ROM, or any other form of storagemedium known in the art. An exemplary storage medium is coupled to theprocessor such that the processor can read information from, and writeinformation to, the storage medium. In the alternative, the storagemedium may be integral to the processor. The processor and the storagemedium may reside in an ASIC. The ASIC may reside in a user terminal. Inthe alternative, the processor and the storage medium may reside asdiscrete components in a user terminal.

In one or more exemplary designs, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by ageneral purpose or special purpose computer. By way of example, and notlimitation, such computer-readable media can include RAM, ROM, EEPROM,CD-ROM or other optical disk storage, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to carryor store specified program code means in the form of instructions ordata structures and that can be accessed by a general-purpose orspecial-purpose computer, or a general-purpose or special-purposeprocessor. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD) and Blu-ray disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. § 112, sixth paragraph,unless the element is expressly recited using the phrase “means for” or,in the case of a method claim, the element is recited using the phrase“a step for.”

What is claimed is:
 1. A stepped-width, co-spiral inductor structure,comprising: a first exterior layer having a first exterior width; afirst interior layer coupled to the first exterior layer, the firstinterior layer having a first interior width that is wider than thefirst exterior width; a second exterior layer coupled to the firstinterior layer, the second exterior layer having a second exterior widththat is narrower than the first interior width; and a second interiorlayer coupled to the first interior layer, the second interior layerhaving a second interior width that is wider than the first exteriorwidth and the second exterior width, in which the second exterior layeris coupled to the first interior layer through the second interiorlayer, and the second interior width is different than the firstinterior width.
 2. The stepped-width, co-spiral inductor structure ofclaim 1, in which the first exterior layer is near a first ground planeof a substrate.
 3. The stepped-width, co-spiral inductor structure ofclaim 1, in which the second exterior layer is near a second groundplane of a substrate.
 4. The stepped-width, co-spiral inductor structureof claim 1, in which the first exterior width is the same as the secondexterior width.
 5. The stepped-width, co-spiral inductor structure ofclaim 1, under an acoustic filter supported by a first ground plane of asubstrate.
 6. The stepped-width, co-spiral inductor structure of claim1, within a package substrate including a first ground plane proximatethe first exterior layer and a second ground plane proximate the secondexterior layer.
 7. The stepped-width, co-spiral inductor structure ofclaim 1, integrated into a radio frequency (RF) front-end module, the RFfront-end module incorporated into at least one of a music player, avideo player, an entertainment unit, a navigation device, acommunications device, a personal digital assistant (PDA), a fixedlocation data unit, a mobile phone, and a portable computer.
 8. Astepped-width, co-spiral inductor structure, comprising: a firstexterior layer having a first exterior width; a first interior layercoupled to the first exterior layer, the first interior layer having afirst interior width that is wider than the first exterior width; asecond exterior layer coupled to the first interior layer, the secondexterior layer having a second exterior width that is narrower than thefirst interior width; a second interior layer coupled to the firstinterior layer, the second interior layer having a second interior widththat is wider than the first exterior width and the second exteriorwidth, in which the second exterior layer is coupled to the firstinterior layer through the second interior layer; and a third interiorlayer coupled between the first interior layer and the second interiorlayer, the third interior layer having a third interior width that iswider than the first interior width and the second interior width, inwhich the second interior width equals the first interior width.
 9. Amethod of fabricating a stepped-width, co-spiral inductor structure,comprising: fabricating a first exterior layer having a first exteriorwidth in a substrate by: patterning the first exterior layer and etchinga conductive material in the substrate according to a first exteriorspiral pattern having the first exterior width as a first exteriorspiral inductor; fabricating a first interior layer coupled to the firstexterior layer in the substrate, the first interior layer having a firstinterior width that is wider than the first exterior width by: etching afirst via opening in a first separation layer to expose the firstexterior layer; patterning the first separation layer according to afirst interior spiral pattern having the first interior width;depositing a conductive material in the first via opening and thepatterned first separation layer; and etching the conductive material inthe patterned first separation layer as a first interior spiral inductorcoupled to the first exterior layer through the first via opening; andfabricating a second exterior layer coupled to the first interior layerin the substrate, the second exterior layer having a second exteriorwidth that is narrower than the first interior width.
 10. The method ofclaim 9, in which fabricating the second exterior layer comprises:etching a second via opening in a second separation layer to expose thefirst interior spiral inductor; patterning the second separation layeraccording to a second exterior spiral pattern having the second exteriorwidth; depositing the conductive material in the second via opening andthe second patterned separation layer; and etching the conductivematerial in the patterned second separation layer as a second exteriorspiral inductor coupled to the first interior spiral inductor throughthe second via opening.
 11. The method of claim 9, further comprising:integrating the stepped-width, co-spiral inductor structure into a radiofrequency (RF) front-end module; and incorporating the RF front-endmodule into at least one of a music player, a video player, anentertainment unit, a navigation device, a communications device, apersonal digital assistant (PDA), a fixed location data unit, a mobilephone, and a portable computer.
 12. A radio frequency (RF) front-endmodule, comprising: a stepped-width, laminate inductor structure,comprising a stepped-width, co-spiral inductor structure in a substrate,the stepped-width, laminate inductor structure including a firstexterior layer having a first exterior width, a first interior layercoupled to the first exterior layer, the first interior layer having afirst interior width that is wider than the first exterior width, and asecond exterior layer coupled to the first interior layer, the secondexterior layer having a second exterior width that is narrower than thefirst interior width, in which the second exterior width is differentthan the first exterior width; and a duplexer supported by thestepped-width, laminate inductor structure.
 13. The RF front-end moduleof claim 12, further comprising a second interior layer coupled to thefirst interior layer, the second interior layer having a second interiorwidth that is wider than the first exterior width and the secondexterior width, in which the second exterior layer is coupled to thefirst interior layer through the second interior layer.
 14. The RFfront-end module of claim 13, in which the second interior width equalsthe first interior width.
 15. The RF front-end module of claim 13, inwhich the second interior width is different than the first interiorwidth.
 16. The RF front-end module of claim 12, incorporated into atleast one of a music player, a video player, an entertainment unit, anavigation device, a communications device, a personal digital assistant(PDA), a fixed location data unit, a mobile phone, and a portablecomputer.